Pope prays for JFK's sister hospitalized in Mass.

Pope Benedict XVI was praying for former President John F. Kennedy's sister Eunice Kennedy Shiver on Monday as she remained hospitalized in critical condition, a Vatican ambassador said.

Shriver, 88, has been hospitalized since last week. Members of her extended family, including California Gov. Arnold Schwarzenegger, who's married to her daughter, Maria Shriver, have gathered at her bedside at Cape Cod Hospital in Barnstable.

The pope's representative to the United States, Archbishop Pietro Sambi, on Monday wrote a letter to Shriver's husband and their five children, members of one of the country's most prominent Roman Catholic families.

"His Holiness unites himself spiritually with each of you at this difficult time, holding close Eunice as she is called home to eternal life and trusting in the words of Sacred Scripture: What will separate us from the love of Christ?" said the letter, which was released to The Associated Press.

The pope prayed Shriver would be rewarded for her ardent faith and generous public service, particularly for those who are physically and mentally challenged, the letter said.

Shriver, inspired in part by the struggles of her mentally disabled sister, Rosemary Kennedy, organized the first Special Olympics in 1968. The two-day event, in Chicago, drew more than 1,000 participants from 26 states and Canada.

The 2007 Special Olympics World Summer Games, in Shanghai, involved more than 7,500 athletes from 164 countries.

In July, President Barack Obama met the pope at the Vatican and gave him a letter from Sen. Kennedy, who was diagnosed a year ago with brain cancer. Aides said Obama asked the pope to pray for Kennedy, a political ally.